The invention relates to an endoscopic visualization apparatus having a first imaging system and having at least one second imaging system, a first image field being covered by the first imaging system, and a second image field being covered by the second imaging system, and the imaging systems being arranged in a common housing.
An endoscopic visualization apparatus of the type mentioned at the beginning is used, for example, as an observation system for medical purposes in what is termed minimally invasive surgery. In the case of standard operations such as, for example, laparoscopic cholecystectomy, access is usually made to the abdominal cavity via three small incisions artificially created in the abdominal wall. One of the three openings serves for introducing the visualization apparatus, for example an endoscope, while the operating instruments, for example tubular shaft instruments, are introduced into the abdominal cavity via the two other openings. The surgical operation is executed by the instruments guided by the surgeon, under visual control via the monitor on which the image supplied by the endoscopic visualization apparatus is displayed. The endoscopic visualization apparatus itself is operated by the assistant staff and controlled in terms of position such that the operating area of the operating instruments is always located in the image field of the visualization apparatus.
There is often the wish to display the operating area on the monitor in an enlarged fashion or from another viewing angle. In order to be able to display the operating area in an enlarged fashion, it is known to use a zoom objective which can be set from the proximal end or distal end, or the endoscope is displaced axially for this purpose. In order to display the operating area from another viewing angle, it is necessary to make consecutive use of various endoscopes with different directions of view. Both the setting of a zoom objective, the axial displacement of the endoscope and the changing of various endoscopes constitute additional manipulations, and thus an additional outlay, and so the operating times are lengthened and the costs of operations are raised because of additional visualization apparatuses.
However, there are known in the prior art arrangements which offer multiple display of the operating area, and thus a remedy with regard to the disadvantages mentioned above.
DE 38 06 190 A1 discloses an electronic endoscope device which comprises an elongated insertion part, two imaging optical systems in the form of two objectives at the distal end of the insertion part, and an imaging apparatus in the form of an electronic imager which is assigned to the two objectives. A stereo view can be obtained with the aid of this known endoscopic visualization apparatus. This endoscopic visualization apparatus therefore comprises two imaging systems which respectively cover an image field. The image fields covered by the two imaging systems are, however, substantially identical and overlap one another essentially completely. The two objectives of the two imaging systems, and thus the latter themselves, are identical for this purpose with regard to their optical properties. The two imaging systems differ from one another only slightly in their directions of view, something which is also necessary so that the two juxtaposed imaging systems cover the same image field in order to obtain a three-dimensional impression of this image field.
An endoscopic visualization apparatus comparable thereto is disclosed in DE 42 41 938 A1, which describes an endoscope with stereo side-viewing optics. In the case of this known visualization system, as well, the image fields of the two imaging systems overlap one another virtually completely, and the imaging systems do not differ from one another with regard to their imaging properties, in order precisely to convey a stereo image or a three-dimensional impression of an observed object. Apart from this stereoscopic information, it is not possible in the case of the two known visualization apparatuses previously mentioned to obtain further image information relating to the operating area.
Furthermore, U.S. Pat. No. 5,166,787 discloses a video endoscope which, in accordance with an exemplary embodiment, has two imaging systems comprising in each case an objective and an electronic imager. In accordance with a variant of this known endoscope, the two imaging systems are capable of producing a stereoscopic effect in which the two imaging systems are pivoted into a position in which the two imaging systems cover two image fields which, once again, overlap one another virtually completely. In accordance with a further alternative, two imaging systems are present in the endoscope, their directions of view differing by 180° such that the image fields covered by the two imaging systems are completely disjunct. Although an overall image field which is larger as a whole is thereby achieved, it is not possible to obtain any additional image information from one and the same observed area. Apart from this, in the case of this endoscope the undesired manipulations already previously mentioned are required in order to move the two imaging systems into the appropriate active position.
It is therefore the object of the invention to develop an endoscopic visualization apparatus of the type mentioned at the beginning to the extent that it is possible to obtain more image information with one and the same visualization apparatus without the need for this purpose of manipulations of the visualization apparatus or even a change of the visualization apparatus.